Separator



May 30, 1939. R. w. GOEB 2,160,498

SEPARATOR Filed July 28 1936 3 Sheets-Sheet 2 v 26 27 l INVENTOR. I RUDOLPH W 6055 I M, n 1

ATTORNEY R. W. GOEB May 30, 1939.

SEFARATOR Filed July 28, 1956 I? Sheets-Sheet 3 INVENTOR.

BY RUDOLPH w. 6058 1. 9 TTORNEY Patented May 30, 1939 UNITED STATES- ATENT OFFICE '7 Claims.

The invention relates to, a method and meansfor utilizinga fluid in the separation of solid particles from a mixture thereof by removing-the particles oflesser specific gravity by suspension in a'conveyor stream of the fiuid.

An object of the invention isto provide an apparatus which is particularly adaptedfor use in the physical separation and concentration ofprecious metals from pulverized or finely divided ores thereof, with a percentage of separating efficiency which is unusuallyhigh' for apparatus of the present type.

Another object is to provide a separator apparatus which is adapted for operation witheil5 ther air or water as a conveyor'fiuid as best suits the conditions under which the apparatus is to be used.

Afurther object is to provide an improved apparatus of the type described in which a suction- 0 head isapplied to a layer of the mixturewhich is moved'beneath the head on a conveyor belt.

An added object is to provide an improved and particularly efficient suction head for apparatus of the class described. I l v The device possesses other objects and featuresof advantage, some of which with theforegoing, will be set forth or be. apparent in the'following description thereof, and in the accompanying drawings, in which,

Figure 1 is a side elevation of an apparatus unit embodying the invention and arranged for operation with air as a separating agent.

Figure 2 is a vertical section taken through the apparatus at its longitudinal axis.

' Figure 3 is a plan view of the apparatus,

Figure lis a transverse stepped section at-the broken line 4-4 in Figure 3.

Figure 5 is a fragmentary transverse section at the broken line 55 in Figure 2.

m Figure 6 is a sectional elevation at 6- -6 in Figure 3, with the apparatus arranged for operation with Water as the separating-medium.

Figure 7 is an enlarged fragmentary longitudinal section through a suction nozzle of the ap- 5- paratus.

Figure 8 is an end elevationof a plurality of apparatus units arranged foroperation together with air as the separating medium.

Essentially, and as illustrated, a unit I l of the 50" present" separator apparatus comprises .a con-' veyor belt or apron l2 on which the comminuted material to be segregated is carried beneath a suction head l3 for the removal of the material W particles of least density.- In its present-embodi- 5 ment, the apparatus has been specifically designed for the treatment of finely divided ore containing particles of th'e'precious metals, particularly. platinum and gold and silver, whereby sand and rock particles are arranged to be removed-from the belt-through the suction head 5 l3-to leave a concentration of metal and metalbearing particles on the belt for their conveyance to a, suitable receptacle therefor. For descriptive convenience,v the following description will be more or less specific to a gold separator 19 and concentrator.

The conveyor belt" l2-is relatively wide, is' continuous, and is mounted on and around horizontallydisposed and mutually parallel rollers or drums Hand-:. Th'e'arrangement is such that l5- an upper belt portion 16* between the rollers is generally horizontal and is'arranged to carry a thinlayer of comminutedore'thereon forwardly and beneath the suction head l3'which is operative against the ore layer intermediately of the 20 belt-supporting rollers. The return belt portion llfmay'beengaged-at-its upper, face by a roller I8which' engages the; belt as a means to keeping the same constantly tensed to the same degree.

For reasons to be hereinafter brought out, the conveyor belt assembly is preferably mounted within a tank-like structure 19 which is open at"v the'top andhas end walls 2| -and 22; side walls 23 and; and a-bottom wall 25 having various portions thereof sloping as funnel sides to a discharge opening 26 for the concentrated material which-fallsfromthe belt as'it passes around the roller 1 5; A" spring-supportedclosure member 21 1s provided at the opening 26 whereby tonormally close-said opening and to be automatically displaced'to'open position when the weight ofmaterial thereon exceeds a limit-which is predetermined" by the strength of the spring 28 whichsupportsone endof the member 27; said member being pivotally supportedfrom the tank bottom at its'gopposite side.

The rollers I4 and'l5 are fixed on shafts 29 and *3Wrespectively, said shafts being journalled in suitable bearings provided on the tank walls 23 and'24" which support the rollers in their. 451

places. Asshown; the shaft 30extends through the wall 24; and its protrudingend carries a belt pulley 32for use in driving the belt. I

The belt-tensing roller l8 is rotatably mounted on a shaft 33,'which shaft is in turn mountedon the ends of arms 3.4"which extend from a rock shafttfi'which is journalled'in and between the tank-walls-23 and 24'; in this manner, the com-- bined weights of theroller IB and its shaft 33 and the arms 34 gravitationally cooperate to con- 5&

stantly and yieldingly exert a belt-tensing pressure against the belt. As shown, the rock shaft 35 extends through the tank wall 24, and its extending end has an arm 36 fixed thereto to extend generally horizontally and to the same side of the shaft as the roller arms 34. The arm 36 carries a suitable weight 31 slidably mounted thereon for fixed adjusted positioning therealong; in this manner, the effective pressure of the roller I8 against the conveyor belt I2 may be adjustably varied as required or desired.

The material to be segregated is arranged to provide the layer on the conveyor belt I2 from a hopper 38 mounted on the tank and which discharges upon a distributing roller 39 in a line extending axially of the roller and at its top. The roller 39 overlies the upper belt portion I6 adjacent its support roller I4 whereby material deposited thereon from the hopper 38 is in turn deposited on the belt in a uniform layer as the roller is rotated.

The roller 39 is fixedly mounted on a shaft 4| which is journalled in the tank walls 23 and 24 and extends beyond both of said walls. The protruding portion of the shaft 4| adjacent the tank wall 23 carries a pulley 42 which is engaged by a drive belt 43, the latter belt being driven from a suitable power source (not shown) such as an engine or electric motor. The other protruding end of the shaft 4| carries a pulley 44 in the plane of the pulley 32 on the shaft 3|], and a belt 45 engages the pulleys 44 and 32 for the driving of the latter from the former. It will be understood that the present arrangement provides for a movement of the conveyor belt I2 in predetermined synchronism with the rotation of the feed roller 39.

It will now be noted that the hopper 38 is in the general'form of a V having its rear wall 46 extending substantially to the surface of the feed roller 39. The fixed front wall 4? of the hopper 38 has a gate plate 48 mounted thereon at its bottom for adjusted positioning with res ect to the roller, it being noted that the bottom dges of the hopper wall 46 and the plate 48 define the discharge outlet for the hopper. The relation of the hopper to the roller 39 is such that the material in the hopper is not discharged therefrom unless the roller is rotating, and the rate of discharge from the hopper is determined by the spacing of the lower edge of the plate 48 from the roller. As shown in Figures 3 and 4 and5, the plate 48 is U-shaped to receive the lower edge portion of the forward hopper wall 41, and is held in adjusted position by means of bolts 49 mounted in the wall 41 and extending through slots 50 inthe plate to receive wing nuts 5| for clamping the plate in set adjusted position. Since the feed roller and belt are operated in fixed speed relations, the adjustability of the plate 48 is understood to solely control the thickness of the layer of material which is deposited on the belt.

Referring now to the structure of the suction head I3, it will be noted that the same comprises a series of nozzles 53 which are mutuallyaligned in the line of the belt. The nozzles 53 extend upwardly from openings 54 in a planar intermediate portion of a flat plate 55, said plate having an upturned rear end portion 55 beyond the rear nozzle opening 54, whereby a layer of material on the belt I2 may wedgedly enter between the plate portion 55' and the belt for its advancement beneath the suction head I3. The plate open-' ings 54 are rectangular, extend across the belt width, and are of successively shorter lengths in the direction of movement of the belt whereby the rearward opening 54 is the larger.

It will be noted that the openings 54 define the intake ends of different nozzle passages 56 and that said passages are contracted upwardly at their rear and front sides to points where they all have the same cross-section, said points defining the tops of the nozzles proper; as shown, the tops of the nozzles lie in a common plane which is parallel to that of the plate 55. The nozzle passages 56 discharge into rectangular riser passages 51 which extend upwardly for certain distances and are then curved forwardly to discharge horizontally into a common passage 58 of the suction head, said last passage being of rectangular cross-section in a vertical plane and discharging into a receiving chamber 59.

It is to be particularly noted that the different riser passages discharge into the passage 58 at successively lower levels, with the rearward riser passage extending to the greater height. For facilitating the selective action to be hereinafter described, the riser passages 51 may gradually and slightly increase in cross-section by reason of an increased separation of their rear and front walls upwardly therein; in this manner, the fluid passages provided by the nozzles and risers are smallest at the nozzle tops, the nozzle and riser passages respectively flaring downwardly and upwardly from the nozzle tops.

As particularly illustrated, the suction head I3 is bounded by flat and vertical side walls 6|, a top wall 52 which is extended downwardly to a junction with the rear end of the plate 55 and is otherwise flat, and a bottom wall 63 which extends from the forward end of the plate 55 to define the lower side of the closed' passage 58. The various nozzle and riser passages are provided within the space defined between the walls 6| and 92 and 63 by means of partitions 64 which extend between the side walls 6 I the whole forming a'unitary assembly.

The receiving chamber 59 is defined by extensions of the walls 6| and 62 and 63 and a vertical front wall 65; preferably and as shown, the wall 63 extends obliquely downwardly and forwardly from the described nozzle assembly whereby the passage 58 and chamber progressively increase in vertical cross-section forwardly of the nozzle assembly. The wall 63 terminates forwardly at a substantially upright wall 66, the latter wall and the opposed portion of the wall 55 cooperating with downward extensions 61 of the side walls 6| to provide an upright discharge passage 68 for the chamber 59, said passage being normally closed by a suitable closure plate 69 at its bottom.

In the arrangement shown in Figures 1 to 5 and 8, the segregation of the particles is arranged to be effected by inducing an air stream through the nozzle and riser passages into the receiving chamber 59. To this end, a suitable air pump is provided at or adjacent the suction head wall 62 for removing air from the chamber 59 and so inducing the desired carrier stream through the suction head. As particularly illustrated, an exhaust fan 19 is mounted on top of the suction head I3 adjacent its front, the intake of the fan being connected with the receiving chamber 59 at an opening I2 provided in the wall 62 whereby the fan I0 may be operative as an air pump with respect to the chamber. A suitable valve 'II is provided in the fan intake foradjustably controlling the flow rate of the air stream into and through the suction head I3. The fan Ill may be belt driven from the pulley of the shaft 39,

as is particularly illustrated; in this manner, all moving parts of th'e'unit are'arranged t0 beactuated from the primary drive belt 43.

Preferably, andas shown, a baflle partition '73 extends downwardly within the chamber l5 from the top wall 62 and in spaced relation to the side 'walls- 6l thereof, whereby'the center portion of the stream ofair entering the chamber through the passage 58 may be directed against the baffle for assisting the gravitational settlement of particles from the air. It will be understood that the aforesaid settling out of particles from the air stream is primarily effected by reason of the slower air motion in the chamber because of its greater cross-section in the'line of movement of the air stream-through the chamber.

The particles which are deposited in the chamber 59" are arranged to reach the discharge passage 68 which is understood to function as a trap. The opening at the bottom of the passage 68 preferably extends for the full width of the suction head, and the closure plate 69 is arranged for a passage-opening displacement thereof under the weight of the accumulated particles thereon. In the present structure, the plate 69 is pivoted forg s'winging about an axis which is parallel to and spaced outwardly from the forward plate edge, and is supported at its rearward edge by means of one or more tension springs 14, the arrangement being such that the passage is opened under the weight of a such a depth of material thereon as will maintain a seal against the suction in the chamber while permitting the gravity escape of the material from the chamber.

It will now be noted that the forward end of the suction head assembly is arranged to be supported on a vertical plate member 15 which is fixed at the front end wall andis provided with feet at its bottom edge. The plate 15 also provides brackets from which the plate 69 is pivotally supported, while the'spring 14 extends from an anchorage at the under side of the wall 63. A bolt 16 connects the spring '74 with the plate 65 whereby the tension of the spring may be adjustably varied.

At its nozzle end, the suction head I3 is 'arranged to be supported on the tank NJ; as brought out in Figures 1 to 3, a support bar 11 extends across the top of the tank and rests uponthe upper edges of the tank walls 23 and 24, and

the barll in turn engages beneath the wall 63 of the suction head for supporting the rearward portionthereof. When the suction head unit I3 is disposed as is shown and now described, the bottom plate 55 of the nozzle assembly is arranged to engage the portion E6 of the conveyor belt l2 for appreciably depressing it belowthe plane which it tends to assume, said plane being tangent to the belt-carrying rollers M and IE; it will thus be understood that the constant tensing of the belt by reason of the action of the roller l8 thereagainst is arranged toyieldingly hold the belt flat against the plate 55.

The belt l2, it will now be particularly noted,

is'arranged to be pervious to the conveyor fluid while retaining thereon the particles of materials -for segregationjin practice it has been "the material thereon. This results in a constant lifting urge on the particles in the air stream,

and a particle which reaches the top of the nozzle will, by reason of the greater stream velocity at the'nozzle top be carried upwardly through the riser passage-and so into the receiving chamber 59.

As the layer of material on the belt l2 moves beneath the rearward suction nozzle, the less dense particles of the layer up to a certain density will be removed, this by reason of the greater downward flaring of the nozzle passage from its top and the greater height of the riser passage from the nozzle. The particles not removed at the first (rear) nozzle are advanced by the conveyor belt to the next nozzle where the particles of the next greater density range are removed through the corresponding riser passage, the process being repeated for the full number of nozzles. In this manner, the final residue on the belt will comprise only the more dense particles which, in the case of the precious metals, lie within the density range thereof which is distinct from the density ranges to be expected in rock particles or sand. For best effecting this selective removal of lighter particles from ore mixtures, it has been found that the areas of the nozzle intake openings 54 should progressively decrease in order by about 15 to 18 percent, with the rear opening 54 the largest.

Since the suction removal of less dense materials from a mixture is primarily a frictioneffect in terms of surface area exposed to a conveying stream of fluid, it is generally desirable that particles to be segregated be first gradedfor size into batches for individual treatment whereby the particles being acted on may not differ too widely as to surface area, and the difference in density will then govern the matter of suction removal of each individual particle in the mixture, larger particles of a given density requiring a greater stream velocity for their removal. Generally speaking, it is preferable that the grading be such that the smallest metal particles in a graded batch of ore would not be lifted with the largest sand and rock particles in the batch. In the use of the present apparatus, particles of sand or rock as large or larger than one-eighthinch across may be readily removed from the belt. Furthermore, the effective suction, as measured with a manometer, need not exceed about two inches of water for removing the larger particles.

The conditions which obtain in the different nozzles of their line during the operation of the suction headare seen to be indicated in Figure '7, it being noted that, by reason of the forcing of the lighter particles upwardly by the air stream Since the full thickness of the layer of material on the belt must pass beneath the rearward portion 55 of the plate 55 which provides the nozzle intake openings, and but a relatively smallamount of treated material remains on the belt forwardly of the nozzles, it is generally pref erable that the urge to press the belt against the plate 55 be less at the rearward portion of the plate. This. is accomplishedby disposing the nozzle assembly closer to the forward support line-forthe be1t-than-to a rearward support line;

in the present instance the front support line referred to is the line of tangency of the belt with the forward roller 15, and the rearward support line is provided at the top of a cylindric sleeve '18 which tangentially engages the belt between the nozzle assembly and the rear roller I4 with its support line lying in the previously mentioned plane which is tangent to the rollers I4 and I5 at their upper sides. By shifting the suction head unit It longitudinally with respect to the belt, the difference of pressure engagement of the belt at the front and rear ends of the plate 55 may be adjustably varied as required or desired. As shown, the sleeve 78 is mounted on a bolt member '29 which extends through and between the tank walls 23 and 24, the sleeve 18 functioning as a spacer element between. the walls.

By reference to Figure 6, it will be noted that the present unit is therein shown as particularly arranged forhydraulic operation. In this instance water may be supplied to the tank l9 through a pipe 8! which is connected at an opening 82 provided in the rear tank wall 2|. A suitable overflow, such as a spout 33, is provided at an upper point of the wall 2! for maintaining a constant water level in the tank, it being understood that water would be supplied to the tank at a faster rate than it is removed through the suction head whereby to insure a maintenance of the desired water level substantially in the plane of the nozzle tops; Under hydraulic operating conditions, the mixture in the hopper 38 would preferably be wet to facilitate its underwater distribution on the conveyor belt.

It will now be noted that the discharge passage 68 for the receiving chamber 59 is at a somewhat lower level than the water level which is arranged to be maintained in the tank I!) and that a valved outlet pipe 8 5 is provided for said passage whereby, if the suction head be full of water, the opening of the valve. 35 in the pipe 84 will provide a siphoning flow of water from the tank through the belt and suction head to remove the lighter particles as. when air is used as a conveyor fluid; The valve 85 would, of course, be adjusted to provide the desired segregating action of the head. Since under these circumstances the suction head must be air-tight except at the intake provided for the nozzles and the discharge provided at the valve 85, the opening for the air pump connection may be sealed with a plate 86, as is particularly shown.

For starting the described siphon flow of a conveyor stream of water through the suction head it is merely necessary to close the valve 85 and remove the air from the suction head. The latter is arranged to be accomplished by opening a valve 8'! in a pipe 88 which is connected between the top of the chamber 59 and a suitable air exhaust pump (not shown); when the air is exhausted from the chamber 58, the latter will" become filled with water, and the subsequent opening of the valve 35 creates the described siphoning of water through the suction head assembly to produce a conveyor stream of water which is the operative equivalent of the previously described air stream.

By reference to Figures 1 and 2 it will be noted that the tank opening 82 is shown as being closed by a plug member 89. While a lateral closing of the tank is not absolutely essential when the present unit is to be operated with an air stream through the suction nozzle, the disposal of the suction head within the present tank minimizes any possible interference of external air currents with the belt supported layer of material to be treated; otherwise, the support means for the described hopper and belt arrangement might comprise an open frame. Also, the water outlet pipe 84 of the embodiment of Figure 6 may be replaced by a plug 9| when the present unit is to be pneumatically operated, such a substitution being shown in the embodiment of Figures 1 to 5 and 8.

Since the process of the present device may involve a treatment of batches of material having particles of difierent size ranges, or repeated treatments of the concentrates which are delivered from the conveyor belt, it may be desirable to provide a plurality of the present units for operation together as a battery thereof. Such an arrangement is illustrated in Figure 8 wherein the suction heads l3 of a number of units are connected with a common exhaust pump 92 and their shafts 4| are connected in line for operation from the same pulley 42. It will be understood that a battery of the hydraulic units of Figure 6 might be correspondingly arranged for operation together.

It will be understood that the pneumatically operated form of the present invention is of particular value for use in concentrating the comminuted ores of precious metals in locations where water is lacking for carrying out the present, or some other, hydraulic process. In the use of the present apparatus, the percentage of physical recovery of precious metals has been found to be approximately 99 percent, whereby a particularly effective device for ore concentration has been provided.

From the'foregoing description taken in connection with the accompanying drawings, the advantages of the construction and method of operation of the present device will be readily understood by those skilled in the art to which the invention appertains. While I have described the features and use of the device in what I now consider to be preferred embodiments thereof, I desire to have it understood that the showings are primarily illustrative, and that suchchanges may be made as fall within the scope of the following claims,

1. In a separator of the class described. a conveyor belt for materials to be segregated, and a suction head overlying said belt and providing a succession of downwardly opening suction nozzles aligned along the belt and providing inlet openings of uniform width across the belt, successive said openings being progressively narrower in the direction of movement of the belt at the nozzles.

2. A structure in accordance with claim 1 wherein the suction head provides a succession of riser passages of uniform and like cross-section into diiferent ones of which the passages of the different nozzles discharge.

35A structure in accordance with claim 1 wherein riser pipes having passages of like crosssection are connected to the upper ends of the nozzles and said riser pipes discharge horizontally at progressively lower levels.

4. In an hydraulic separator of the class described, a conveyor belt for supporting and carrying a layer of particles to be segregated, a suction head operative against the layer of particles on the belt and comprising a suction nozzle operative at said layer and a receiving chamber connected with the nozzle by a riser pipe, a water tank receiving the nozzle and the belt portion thereat, means operative to maintain a constant water level in said tank and above the nozzle mouth, and an outlet for said receiving chamber discharging into the atmosphere below the level of water in the tank whereby to siphon water from the tank for creating a water stream in the suction head and through the layer of particles on the belt for removing the less dense particles in the stream.

5. A structure in accordance with claim 4 wherein an adjustable valve is provided in the water discharge outlet for adjustably controlling the flow rate of the stream.

6. In a separator of the class described, a fluidpervious conveyor belt having a portion thereof carrying a layer of particles for separation, a suction nozzle having its mouth in fiat and positive pressure engagement with said belt portion and operative to deflect the belt out of the line which it would otherwise assume, and a plate element extending obliquely upwardly and rearwardly from the rearward nozzle side at its bottom and in angular relation to the belt thereat whereby the particles on the belt are arranged to be wedgedly introduced beneath the nozzle as the belt thereat passes forwardly beneath the nozzle.

7. In a separator of the class described, a fluidpervious conveyor belt carrying a layer of particles for separation, a suction head positively enaging said belt from above and providing a succession of downwardly opening suction nozzles aligned along the belt, a shoe plate fixedly mounted on and extending between the nozzles at their lower extremities and provided with openings which register with the nozzle passages and provide the intake openings of the nozzles, the plate being otherwise imperforate and providing the belt-engaging bearing face of the suction head and having an obliquely upturned portion thereof disposed rearwardly of the rearward nozzle and having its under face defining an acute angle with the opposed belt portion whereby the particles on the belt are arranged to be wedgedly introduced beneath the suction head as the belt portion thereat passes forwardly beneath the belt-engaging face of the plate.

RUDOLPH W. GOEB. 

